1. Field of the Invention
The invention relates to a metal-doped ruthenium oxide material and methods of preparing the same.
2. Related Art
Water electrolyzers based on proton exchange membrane (PEM) technology offer several advantages for hydrogen production (1-3). In a PEM-based electrolyzer, water is oxidized into oxygen and protons at the anode. The protons resulting from the electro-oxidation of water are transported through the PEM and combined at the cathode to form hydrogen. When developing advanced PEM electrolyzers, a catalyst that can enhance the production of oxygen gas at the anode would increase the electrolysis efficiency. A desirable oxygen evolution catalyst would have a low overpotential for oxygen evolution, high surface area, and long-term mechanical stability (4). It has previously been reported that a catalyst based on a non-stoichiometric ruthenium oxide enhances the electrolysis of water (5). Also iridium ruthenium oxide catalysts are known to be active towards oxygen evolution (6-8).
Although it is known that ruthenium oxide can be an efficient catalyst for the anodic oxidation of water to oxygen, one issue with ruthenium oxide is that it is not stable in acidic media at oxygen evolution potentials and as such degrades rapidly with use resulting in loss of performance of the PEM electrolysis unit. A stabilized and/or active ruthenium oxide catalyst is thus highly desirable. Catalysts for water electrolysis based on iridium and ruthenium oxide are commercially available, but information for preparing these proprietary materials has not been provided.